Life preserving devices



July 25, 1961 R. SWlTLlK 2,993,217

LIFE PRESERVING DEVICES Filed July 18, 1957 2 Sheets-Sheet 1 INVENTOR. Fa/mm: .S'W/TA/ r W. mv au HTTWF/VEVJ' July 25, 1961 R. SWITLIK 2,993,217

LIFE PRESERVING DEVICES Filed July 18, 1957 2 Sheets-Sheet 2 Armmw q iteThe present invention relates to life preserving devices such as lifebelts, life vests, floats, rafts and the like and more particularly todevices of the type having cells adapted to be inflated by a gas.

In life preservers of this type the cells are usually made of a thin,flexible, coated fabric such as nylon impregnated with natural orsynthetic rubber or other similar plastic. The cell or cells are thenfolded into a compact mass and inserted into pockets of a belt or vestadapted to be attached to the body. The gas to inflate the cells isstored at high pressure in a small container either in the form of a gasor as condensed liquid. When such gas or liquid expands from the highpressure in the container to a low pressure in the cell, its temperatureis reduced to a degree corresponding to the difference in pressure.Liquid carbon dioxide, commonly used for this purpose, boils at 109 F.at atmospheric pressure. Due to the relatively small quantities of gasrequired to inflate a cell, the gas is quickly superheated after leavingthe container by the transfer of heat fro-m the fabric of the cell whichit contacts.

It has been discovered that when the coated fabric material forming thewalls of the cell is chilled below a certain temperature it becomesbrittle and is apt to crack when flexed as it unfolds. Furthermore, ithas been discovered that when the gas expands from the pressurecontainer into the cell the expansion is many times confined tolocalized areas due to the folding of the fabric. As a result, the gasimpinges the fabric at one or a few localized areas over a substantialperiod of time at the extremely low temperature of the expanding gas andchills the fabric material at those localized areas below the criticaltemperature at which it is apt to crack. Such cracks in the expandedcell permits the gas to leak therefrom.

One of the objects of the present invention is to provide a ditfuser inthe inflatable cell for more uniformly distributing the gas throughoutthe cell when it is released from the container.

Another object is to provide a diffusing baffle for unfolding thematerial of the cell before the gas is released therein.

Another object is to provide a diffusing bathe in the cell against whichthe gas initially impinges before it enters the body of the cell so thatany cracking will occur in the diffusing baffle instead of in thematerial of the surrounding cell.

Still another object is to provide a cell of the type indicated which isof simple, light weight and compact construction and one which isreliable in operation and adapted for economical manufacture.

These and other objects will become more apparent Patent G from thefollowing description and drawings in which 7 manner in which theflexible material of the cell is first folded;

FIGURE 3 is a view similar to FIGURE 2 showing the cell folded into acompact mass;

FIGURE 4 is a sectional view showing the folded cell in a pocket on thebelt;

FIGURE 5 is an end view of the folded cell illustrated in FIGURE 3 andshowing the manner in which the cell is initially unfolded;

FIGURE 6 is a sectional view taken on the line 66 of FIGURE 2 to showthe separate chambers in the diffusing baflie in the cell and the pathof flow of the gas through the bafile from the pressure container to thecell;

FIGURE 7 is a plan view of the diffuser baflle partly in section showingthe separate chambers in the baflie and the stitching at the ends toprovide a plurality of small outlet openings; and

FIGURE 8 is a transverse sectional view taken on the line 88 of FIGURE 7to show the separate chambers of the diffuser batfle and the pluralityof outlet openings between the stitches.

The present invention is shown applied to a life belt but it will beunderstood that it may be applied to any type of life preserving devicehaving an inflatable cell. The illustrated embodiment shown in FIGURE 1comprises a belt 10 adapted to be wrapped around the waist of the wearerand attached by a buckle 11 at the ends. A harness 12 is attached to thefront and rear of the belt which is adapted to be applied over theshoulders of the wearer. Pockets 13 and 14 are provided at each side ofthe belt for containing an inflatable cell 15. As shown in FIGURE 2,each cell 15 is of generally rectangular shape having a narrow centralportion 16 and outwardly projecting lobes 17 at each side of the centralportion. Thus, the narrow central portion 16 is adapted to underlie thearms of the wearer and the lobes 17 at each end overlie the front andback of the shoulders of the wearer to hold it in place under the arms.The cells 15 are attachedto the pockets 13 and through the pockets tothe belt 10 by means of fasteners 18 as the cells 15 are composed of acoated fabric such as nylon impregnated with a suitable material such asnatural or synthetic rubber. Each cell 15 is sealed by cementing twolayers of the coated fabric around their marginal edge. As shown inFIGS. 2 and 5 a cylinder 20 containing an expansible liquid, such ascarbon dioxide, is connected to the interior of the cell. An actuatinglever 21 is mounted on the cylinder 20 for breaking a seal in thecylinder to permit the carbon dioxide contained therein to flow into theinterior of the cell 15. A lanyard 22 is attached to the lever 21 formanual actuation.

The deflated cell 15 with the cylinder 20 attached thereto is folded andpacked in a pocket 13 or 14-. To this end, the lobes 17 of the cell 15are first folded on the dot-and-dash lines MM to the position indicatedin FIG- URE 2. The partially folded cell 15 is then folded on the linesNN and PP of FIGURE 2 to form the packet illustrated in FIGURE 3. Thefolded packet of FIG- URE 3 is then inserted into the pocket 13 or 14 asillustrated in FIGURE 4. Each of the pockets 13 and 14 are formed bysides which are held in overlapping relationship by a detachable snapfastener 23 adapted to automatically release to open the pocket when thecell is expanded.

In accordance with the present invention a diffuser bafile 25 isprovided in each cell 15. As shown in FIG- URE 2, the diffuser baflle 25is of generally rectangular shape with curved ends and of less widththan the relatively narrow central portion 16 and a length to extendbeyond the fold lines NN and PP. As shown in FIG- URE 6, the diffuserbaffle 25 is enclosed within the sides 26 and 27 of the cell envelope15. Baffle 25 comprises three superimposed sheets or layers 28, 29 and31 of a thin flexible material such as a rubberized fabric. Preferably athin nylon fabric is used having a rubber coating on each side.

Referring to Figure 8, the three layers 28, 29 and 30 are formed byfolding a single sheet of the coated fabric back on itself. Theoverlapping edge portions of the folds or layers 29 and 30 are cementedaround the entire periphery of the baffle by a rubber cement asindicated at 31 to form a chamber 32. The layers 28 and 29 are alsocemented at the overlapping free edge as indicated at 33 to form asuperimposed chamber 34 open at its opposite ends. The open ends 35 and36 are, in turn, partially closed by stitching as illustrated at 37 and38 which form a plurality of outlet port openings 39 between eachstitch. As shown in FIG. 7, the stitching 37 and 38 may have interruptedportions to provide long stitches 40 at spaced intervals to providelarger port openings 41.

The intermediate layer 29 between the chambers 32 and 34 has a pluralityof port openings 42 therein. In the illustrated embodiment as shown inFIGURES 6 to 8, three pairs of such openings 42 are provided in theintermediate layer or wall 29 through which gas must flow from thechamber 32 to the chamber 34 and then from the chamber 32 through theport openings 39 and 41 at the ends of the diffuser baflie. The diffuserbaffle 25 is attached to one wall of the cell envelope by means ofcement applied at the areas 43 as illustrated in FIG- URE 7.

As shown in FIGURES 6 and 8 the diffuser baflie 25 has a fitting 44 witha nipple 45 extending to the wall 30. To this end, the fitting 44 has adisc 46 at its inner end overlying the inside surface of the wall 30 ofthe diffuser bafile with the nipple 45 projecting through a hole 47. Asimilar disc 48 overlies the outside of the wall 30 of the difiuserbaffle 25 and over the inside of the wall 27 of the cell envelope. Thewall 27 of the cell envelope and the wall 36 of the diffuser baffle 25are then joined to the discs 46 and 48 with cement to form an hermeticseal. The outwardly projecting end of the nipple 45 is threaded at 50 toreceive the pressure container 20 in the form of a cylinder which isscrewed thereon. One form of the invention having now been described indetail the mode of operation is next explained.

The life belt with a folded cell contained in each pocket 13 and 14 isapplied around the waist of the wearer. In applying the belt 10, thewearer inserts his arms through the harness 12 and fastens the buckle 11at the front of the waist. The pockets 13 and 14 containing the cells 15then underlie the arms of the wearer.

When the cells 15 are to be inflated, the lanyards 22 are pulled torelease the liquid carbon dioxide in each of the cylindrical containers20. Upon release and a reduction in pressure, the liquid carbon dioxideimmediately evaporated at a low temperature, corresponding to the lowpressure in the cell, at approximately 110 F. In evaporating the liquidcarbon dioxide absorbs the latent heat of vaporization from the materialwhich it contacts. Furthermore, the release of the high pressure gascauses it to flow at high velocity.

As the gas flows from the cylindrical container it first enters thechamber 32 of the diifuser baffle at high velocity and directly impingesthe intermediate Wall 29. The gas then flows in all directions in thechamber 32 with considerable turbulence as indicated by the arrows inthe chamber in FIGURE 8. The port openings 42 in the wall 29 between thechambers 32 and 34 restrict the flow of the gas from one chamber to theother which causes the folded over ends of the diffuser baffle 25 tounfold and thereby unfold the overlapping portions of the cell envelopein the manner as shown in FIGURE 5. As soon as the diffuser baffle 25unfolds the gas flows from the upper chamber 34 through the portopenings 39 and 41 between the stitches 37, 38 and 40 at the oppositeends of the chamber. Thus, the flow of gas from the diffuser baflie 25into the cell 15 is produced through a large number of small portopenings to diffuse the gas over a large area and prevent localizedimpingement of the relatively cold gas with any particular area of thecell envelope 15.

Furthermore, the relatively cold gas leaving the cylinder 2% is heatedby its contact with the walls 28, 29 and 30 of the diffuser baffle 25before it enters the cell 15 so that its temperature is raised above theminimum at which damage is caused to the impermeable coating on the cellenvelope. In other words, the cold gas leaving the cylindrical container24 at substantially l: 10 F. immediately contacts the relatively warmwalls 28, 29 and 30 of the diffuser baffle 25 before entering the cell15 which heats the gas to some temperature such as -50 F. before itleaves the diffuser baffle. Also, the diffuser baffle 25 reduces thevelocity of the gas and discharges it over a large area so that largequantities of gas will not impinge localized spots of the envelope ofthe cell at a high velocity. Thus, cracking of the material of the cellenvelope is avoided. Furthermore, any cracking of the plastic coatedfabric, due to low temperature gas, will occur in the walls of thediffuser baffle 25 which is entirely enclosed and hermetically sealed inthe envelope of the cell 15. Thus, cracking of the walls of the diffuserbaffle 25 will have no effect on the hermetic seal of the cell envelope.

While a single embodiment of the invention is herein illustrated anddescribed, it will be understood that changes may be made in theconstruction and arrangement of elements without departing from thespirit or scope of the invention. Therefore, without limitations in thisrespect the invention is defined by the following claims.

I claim:

1. In a life preserver, an inflatable cell having overlying walls of athin, flexible and impervious material adapted to be folded into acompact mass, a container for storing gas at high pressure and connectedto the cell, a control element for releasing the gas in the containerwhich flows to and inflates the cell, a diffusing baffle in said cellconnected to receive the gas from the container, and said diffusingbafile being composed of an impervious material and forming a chamberbetween the overlying walls of the cell and having a plurality ofrelatively small outlet openings at its edges to diffuse the gas over arelatively large area as it enters the cell.

2. In a life preserver, an inflatable cell having overlying walls of athin, flexible and impervious material adapted to be folded into acompact mass, a diffusing bafiie sleeve of a thin flexible materialforming a chamber within said cell between the overlying walls andadapted to be folded with said cell, said diffusing baffle sleeve havingperipheral openings at its ends, a container for storing gas at highpressure at the exterior of the cell and having a nipple connected tothe interior of said diffusing baffie sleeve, a control element forreleasing gas from the container at high pressure which flows to thechamber of the diffusing baffie and then through the peripheral openingsin the chamber to the cell, and said gas first inflating the chamber ofthe diffusing baffle to unfold the walls of the cell before the gas isdelivered thereto.

3. In a life preserving device, an inflatable cell of a thin flexiblematerial, a container at the exterior of said cell and having a nippleconnected to the interior of said cell, said container storing asubstance at high pressure having a gaseous phase at atmosphericpressure and temperature, and a bafiie in said cell and located at theoutlet end of said nipple against which the high pressure gas from saidcontainer initially impinges before contacting the material of saidcell, said baffie having gas-impervious walls positioned between theoutlet end of the nipple and walls of the cell and forming a passagewayfor the gas opening into the cell at a point remote from the nipple, andsaid baflle comprising a plurality of walls of a flexible imperviousmaterial so joined as to provide a plurality of adjacent chambers, andport openings so arranged in said chambers as to cause the gas tosuccessively change its direction of movement as it flows from thecontainer through successive chambers and into the cell.

4. In a life preserving device, an inflatable cell of a thin flexiblematerial, a container at the exterior of said cell and having a nippleconnected to the interior of said cell, said container storing asubstance at high pressure having a gaseous phase at atmosphericpressure and temperature, and a baffie in said cell and located at theoutlet end of said nipple against which the high pressure gas from saidcontainer initially impinges before contacting the material of saidcell, said bafile having gas-impervious walls positioned between theoutlet end of the nipple and walls of the cell and forming a passagewayfor the gas opening into the cell at a point remote from the nipple, andsaid baflie comprising a plurality of super-imposed walls of a flexibleimpervious material so joined at their periphery as to provide aplurality of adjacent chambers through which the gas must flow from onechamber to another, and a plurality of outlet openings at the peripheryof the last chamber.

5. In a life preserving device, an inflatable cell of a thin flexiblematerial, a container at the exterior of said cell and having a nippleconnected to the interior of said cell, said container storing asubstance at high pressure having a gaseous phase at atmosphericpressure and temperature, and a bafie in said cell and located at theoutlet end of said nipple against which the high pressure gas from saidcontainer initially impinges before contacting the material of saidcell, said batlie having-impervious walls positioned between the outletend of the nipple and walls of the cell and forming a passageway for thegas opening into the cell at a point remote from the nip ple, and saidbafile comprising a plurality of super-imposed walls of a flexibleimpervious material, two of said walls being joined around their entireperiphery to form a chamber therebetween, another of said superimposedwalls being joined to an adjacent one of said last mentioned walls attwo opposite edges, the other two opposite edges of said last named wallbeing joined to the adjacent wall to form a second chamber with aplurality of outlet openings therebetween, and the intermediate wallbetween the chambers having a plurality of restrictive openings thereinwhereby gas is caused to flow from the first mentioned chamber to thesecond mentioned chamher and then through the outlet openings insuccessively changing directions in its path of flow.

6. A life preserving device in accordance with claim 5 in which the lastnamed wall is joined to the adjacent intermediate wall by stitching toprovide a plurality of outlet openings between stitches.

7. A life preserving device in accordance With claim 6 in which the lastnamed wall is joined to the adjacent intermediate wall by alternateseries of short and long stitches.

8. A life preserving device in accordance with claim 5 in which theplurality of walls are formed by a single sheet of material reverselyfolded with the free edges joined to the folds.

9. A life preserving device in accordance with claim 8 in which theadjacent walls are joined at their periphery by cement.

References Cited in the file of this patent UNITED STATES PATENTS2,118,165 Christopher et al May 24, 1938 2,580,639 Baker Jan. 1, 19522,675,143 Seemann Apr. 13, 1954 2,710,978 Alderfer June 21, 1955 UNITEDPATENT. OFFICE CERTIFICATE OF CORRECTION Patent No. 2,993,217 July 25,1961 Richard Switlik It is hereby certified that error appears in theabove numbered patent requiring correction and that the said LettersPatent should read as corrected below.

Column 5, lines 37 and 38, for "having-impervious? read havinggas-impervious Signed and sealed this 23rd day of January 1962.,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents

